This invention relates to an actuation system for a blocker door used to redirect airflow and more particularly but not by way of limitation to a system for opening and closing a blocker door in a jet engine nacelle.
Heretofore, when a power actuator translated a thrust reverser sleeve assembly on an engine nacelle, a drag link was connected to each blocker door by a spring loaded fitting on the sleeve assembly. The other end of the drag link was connected to a fitting on the inner fan duct wall of the nacelle. As the sleeve assembly is translated, one end of the drag link is rotated on the inner wall fitting. The other end of the drag link is rotated on the blocker door fitting which forces the blocker door to rotate about its hinge and block the airflow in the fan duct. As the sleeve assembly is translated rearwardly, the cascades are exposed. The blockage of airflow by the blocker door causes the fan air to exit through the cascades resulting in a desired thrust reversal.
The primary problem in this type of operation was the drag links pass through the fan air duct disrupting the airflow which resulted in a performance penalty. Also, the drag link and its attachments have had service problems due to the unpredictable effect of the airflow upon the drag link. Further, with drag link and fittings exposed upstream in the fan duct, there are aerodynamic drag loss.
The subject invention eliminates the above mentioned problems in the opening and closing of blocker doors. In the following U.S. patents: U.S. Pat. No. 3,262,268 to Beavers, U.S. Pat. No. 3,603,211 to Medawar et al, U.S. Pat. No. 3,612,209 to Vdoviak, U.S. Pat. No. 4,020,291 to Sarigisson U.S. Pat. No. 4,147,029 to Sargisson and U.S. Pat. No. 4,346,973 to Lawson various types of thrust reverser sleeve assemblies are disclosed having fluid pressure cylinders and pistons for opening and closing blocker doors. None of these prior art patents specifically disclose the unique features and advantages of the subject actuation system as described herein.